| 摘要 |
<p>PURPOSE:To enhance the mass-productivity of floats, by welding two halves of the synthetic resin float such that the two halves are welded by heat, at first excepting one part thereof and then the remaining part thereof is welded by heat so that the pressure in the hollow space of the float which is generated during welding at the first time is relieved. CONSTITUTION:A ring-like float made of synthetic resin is formed such that a lid 4 is fitted in a U-like cross-sectioned shape body 1 and then they are welded together by heat. At this stage the outermost stepped part 4a of the lid 4 is fitted into the opening 1a of the body 1, and is welded by heat, excepting one part thereof. At this time the inside space of the float is heated so that air in the space expands to exhibit a force which tends to separate the welded part. However, the pressurized air is released to the outside through the unwelded part. Thereafter the unwelded part is welded by heat to complete the manufacturing of the float.</p> |
